1. Field of the Invention
The present invention relates to a cassette storing therein a radiation conversion panel for converting a radiation that has passed through a subject into radiation image information, and a radiation image capturing system.
2. Description of the Related Art
In the medical field, there have widely been used radiation image capturing apparatus which apply a radiation to a subject and guide the radiation that has passed through the subject to a radiation conversion panel, which captures a radiation image from the radiation. Known forms of the radiation conversion panel include a conventional radiation film for recording a radiation image by way of exposure, and a stimulable phosphor panel for storing a radiation energy representing a radiation image in a phosphor and reproducing the radiation image as stimulated light by applying stimulating light to the phosphor.
The radiation film with the recorded radiation image is supplied to a developing device to develop the image, or the stimulable phosphor panel is supplied to a reading device to read the radiation image as a visible image.
In the operating room or the like, it is necessary to read out a recorded radiation image immediately from a radiation conversion panel after the radiation image is captured for the purpose of quickly and appropriately treating the patient. As a radiation conversion panel which meets such a requirement, there has been developed a radiation detector having a solid-state detector for converting a radiation directly into an electric signal or converting a radiation into visible light with a scintillator and then converting the visible light into an electric signal to read out a detected radiation image.
Such a radiation image capturing system is disclosed in Japanese Laid-Open Patent Publication No. 2002-248095, for example. In the radiation image capturing system, a radiation source for radiating X-rays is disposed above a patient lying on a lying table, and an electronic cassette is disposed between the lying table and the patient. The electronic cassette includes a phosphor for converting X-rays into an amount of visible light proportional to the intensity of the X-rays and a photoelectric transducer for converting the visible light into an electric signal proportional to the intensity of the visible light. The X-rays radiated from the radiation source pass through an affected area of the patient, and are detected by the phosphor of the electronic cassette and converted into visible light. The visible light is converted by the photoelectric transducer into an electric signal, thereby generating an image signal representing a radiation image of the affected area of the patient.
According to the radiation image capturing system disclosed in Japanese Laid-Open Patent Publication No. 2002-248095, the electronic cassette is disposed between the lying table and the patient at a position that is aligned with the affected area of the patient. If the patient moves while the X-rays are being applied to the patient, then the captured radiation image is blurred, and hence a proper radiation image cannot be produced using the electronic cassette. When the radiation image capturing system thus fails to capture a proper radiation image of the patient, it is necessary to use a new electronic cassette to perform the radiation image capturing process again. Such a repetitive action is tedious, time-consuming, and inefficient.